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Tobias Laux has been awarded the prestigious Stanley Gray Fellowship for his PhD research into testing composite materials in order that they might be used in marine applications. The research will advance knowledge of multiaxial testing of composites and will increase the confidence in composite design, which will enable the uptake of economical lightweight composite solutions in the marine industry and beyond. Benefits may be accrued, for example, through weight reductions on small craft and ships, leading to reduced fuel consumption or higher performance, reduced maintenance or increased service life.

Tobias has a BEng Yacht and Powercraft Design from Southampton Solent University and an MSc Maritime Engineering from the University of Southampton.

“I grew up in the Swiss countryside, pretty much as far away from the sea as it can get in Europe, and a career in marine engineering was likewise remote. However, thanks to my parents’ sailing boat on Lake Zurich I discovered my passion for sailing in early childhood. I was immediately hooked by its blend of engineering, science and technology combined with an adventurous outdoor activity. I have been pursuing a career in the marine industry ever since, spending my summers working for a local yacht designer or designing, building and racing my own model sailing yacht designs. Finally, this passion brought me to study in Southampton, a well-known place for marine subjects. Receiving the IMarEST Stanley Grey fellowship is a satisfaction, a huge source of motivation and a considerable financial boost for my current PhD research project. Thank You!” Tobias Laux, winner of Stanley Gray Fellowship.

Advanced glass or carbon fibre reinforced polymer composites (FRPs) are established materials in primary load-carrying structures in the aerospace, transportation and energy sectors. They are chosen over traditional engineering materials, e.g. aluminium, for their high stiffness and strength to weight ratios, excellent fatigue properties and corrosion resistance. Some of their benefits have been exploited on a range of marine applications such as fully in composites engineered yachts and small craft, wave energy harvesting buoys, or on components for ships such as superstructures and control surfaces.

At present, structural applications of composites in the marine industry are limited and are often over-designed with large safety factors imposed by stringent regulations that offset the potential advantages. A major reason is the lack of confidence in the current testing methods, which to some extent have been adopted from metal testing. The fact that composites are inhomogeneous, fibrous, highly anisotropic, and discretely layered materials displaying complex and interactive failure modes when subjected to multiaxial loading is ignored. Thus, the development of a testing method for composite laminates to obtain reliable multiaxial experimental data is essential to improve, validate and calibrate current modelling and design approaches.

This PhD project addresses the identified need and aims to define an integrated experimental and computational methodology to characterise advanced composite materials. Thereby, composite specimens are bi-axially loaded using a novel test fixture, the Modified Arcan Fixture (MAF). The resulting complex full field displacement and strain fields are measured by Digital Image Correlation (DIC). The obtained data rich experimental data is than exploited to inform nonlinear finite element models, which predict the ply-by-ply stress fields. The integrated experimental and computational approach is needed due to the complex non-uniform stress states within the composite specimens and allows to obtain a more accurate and broader material characterisation that accounts for the anisotropic, fibrous and layered nature of composite materials.

This research will advance the knowledge of multiaxial testing of composites and will increase the confidence in composite design, which will enable the uptake of economical lightweight composite solutions in the marine industry and beyond. Benefits for marine applications accrue, for example, through weight reductions on small craft and ships leading to reduced fuel consumption or higher performance, reduced maintenance or increased service life.